trees. the fruitage of the plant, and the fuftentation of its ftalk, what means could be used more effectual, or, as I have faid, more mechanical, than what this ftructure prefents to cur eyes? Why or how, without a view to this double. purpose, do two fhoots, of fuch different and appropriate forms, fpring from the fame joint, from contiguous points of the fame ftalk? It never happens thus in robuft plants, or in "We fee not," fays Ray, "fo much as one tree, or shrub, or herb, that hath a firm and strong stem, and that is able to mount up and ftand alone without affiftance, furnished with thefe tendrils." Make only fo fimple a comparison as that between a pea and a bean. Why does the pea put forth tendrils, the bean not; but because the ftalk of the pea cannot fupport itself, the ftalk of the bean can? We may add alfo, as a circumftance not to be overlooked, that, in the pea tribe, these clasps do not make their appearance, till they are wanted; till the plant has grown to a height to ftand in need of fupport. This word "fupport," fuggefts to us a reflection upon a property of graffes, of corn, and canes. The hollow ftems of thefe claffes of plants, are fet, at certain intervals, with joints. 2 C3 joints. Thefe joints are not found in the trunks of trees, or in the folid ftalks of plants. There may be other uses of these joints; but the fact is, and it appears to be, at least, one purpose defigned by them, that they corroborate the ftem; which, by its length and hollownefs, would, otherwife, be too liable to break or bend. Graffes are Nature's care. With these she clothes the earth: with these fhe fuftains its inhabitants. Cattle feed upon their leaves; 'birds upon their smaller feeds; men upon the larger; for few readers need be told that the plants, which produce our bread corn, belong to this class. In thofe tribes, which are more generally confidered as graffes, their extraordinary means and powers of prefervation and increase, their hardiness, their almost unconquerable difpofition to fpread, their faculties of revivifcence, coincide with the intention of nature concerning them. They thrive under a treatment by which other plants are destroyed. The more their leaves are confumed, the more their roots increafe. The more they are trampled upon, the thicker they grow. Many of the feemingly dry and dead leaves of graffes - revive, and renew their verdure, in the spring. In lofty mountains, where the fummer heats are not sufficient to ripen the feeds, graffes abound, which are viviparous, and confequently able to propagate themselves without feed. It is an observation, likewife, which has often been made, that herbivorous animals attach themselves to the leaves of graffes; and, if at liberty in their pastures to range and choose, leave untouched the ftraws which support the flowers *. THE GENERAL properties of vegetable nature, or properties common to large portions of that kingdom, are almost all which the compass of our argument allows to bring forward. It is impoffible to follow plants into their feveral fpecies. We may be allowed, however, to fingle out three or four of these fpecies as worthy of a particular notice, either by fome fingular mechanifm, or by fome peculiar provifion, or by both. I. In Dr. Darwin's Botanic Garden, line 395, hote, is the following account of the vallifneria, as it has been obferved in the river Rhone. 66 They have roots at the bottom of the Rhone. The flowers of the female plant * With. Bot, Arr. vol i. p. 28, ed. zd. float on the surface of the water, and are furnifhed with an elaflic, Jpiral, flalk, which extends or contracts as the water rifes or falls : this rife or fall, from the torrents which flow into the river, often amounting to many feet in a few hours. The flowers of the male plant are produced under water; and, as foon as the fecundating farina is mature, they feparate themfelves from the plant ; rife to the furface ; and are wafted by the air, or borne by the currents, to the female flowers." Our attention in this narrative will be directed to two particulars; firft to the mechanifm, the "elaftic, fpiral, ftalk," which lengthens or contracts itself according as the water rifes or falls; fecondly, to the provifion which is made for bringing the male flower, which is produced under water, to the female flower, which floats upon the furface. The II. My fecond example I take from Withering. Arrang. vol. ii. p. 209. ed. 3. "The cufcuta curopea is a parafitical plant. feed opens, and puts forth a little Spiral body, which does NOT feek the earth to take root; but climbs in a spiral direction, from right to left, up other plants, from which, by means of veffels, it draws its nourishment." The "little "little spiral body" proceeding from the feed is to be compared with the fibres which feeds send out in ordinary cafes; and the comparifon ought to regard both the form of the threads and the direction. They are straight; this is fpiral. They fhoot downwards; this points upwards. In the rule, and in the exception, we equally perceive defign, III. A better known parafitical plant is the evergreen shrub, called the miffeltoe. What we have to remark in it, is a fingular inftance of compenfation. No art hath yet made these plants take root in the earth. Here therefore might seem to be a mortal defect in their conftitution. Let us examine how this defect is made up to them. The feeds are endued with an adhefive quality fo tenacious, that, if they be rubbed upon the fmooth bark of almost any tree, they will ftick to it. And then what follows? Roots fpringing from their feeds, infinuate their fibres into the woody substance of the tree; and the event is, that a miffeltoe plant is produced the next winter *. Of no other plant do the roots refufe to fhoot in the ground; of no other plant do the feeds pof * Ib. p. 203. fefs |